Cosmetic brushes are the main applicators for people applying makeup. Different sorts of makeup require different brushes such as a lip brush, an eye shadow brush etc. In cosmetic applicators currently commercially available, one brush has only one function, so the user needs to buy a set of brushes to achieve a satisfactory makeup application.
In other fields, brushes with more than one set of bristles have been proposed. The bristles typically project sideways from a head end of a handle, in opposite directions, so that either set of bristles can be used without involving the other set. However, this is unsuitable for many cosmetic applications, where a brush with the bristles extending endways from the handle is preferred.